Porsche Enthusiasts Club Forum

Hi, I tried to start my Boxster s this morning,the warning lights flickered and the alarm went off.I have got 10v across the battery. I then tried to put the battery charger on but as soon as i took the lead off the battery the alarm went off, i removed the other lead and the alarm carried on for approx 30 secs.Does the alarm have a back up? Do you think it is a straight flat battery replacement?
Cheers
Paul

Hi Paul

OK...10 VOLTS is not enough... the battery is TOO LOW for the alarm...

I dont know whether your alarm has an internal battery to power it when the main battery is too low or wires cut, but if it had I would expect the alarm to go off once the main battery voltage dropped too much as it would think someone was intefering with the wiring...

Now it depends WHY your battery has gone flat....

Several possibilities....

1, Battery is knackered and not ACCEPTING a charge from your alternator...

2, Alternator is knackered and NOT CHARGING the battery.....

3, Battery is being FLATTENED by some sort of power drain (like possibly that alarm)


You really need to get some charge INTO the battery (several hours minimum on a charger, maybe even overnight) then drive car to a garage to get BOTH the battery and alternator tested...

All the best Brett

Thanks Brett

The car must have a back up battery bacuase when i disconnected the main battery the alarm was still wailing. I have managed to get the battery back up to 12.6 volts , I hope this will get through the night without going off, oh joy

Hi Paul, I've been the victim of a Boxster alarm too mate and how I didn't end up smashing the car up I'll never know! Yes the alarm has got a backup making the problem 10 times worse (can't just disconnect it). Check under your mat on the passenger side footwell and if it is damp then this is very likely to be the problem as this is where the cars brain lives. You need to clear the drain holes on the convertable hood as when they block water gets into the car and all hell lets loose. I've also had the car running like a bag of spanners due to this problem. If you read about it on the internet you may panic because alot of people will tell you that it's goosed but take my word for it mate my car has spent most of it's life (1999 S plate) in Manchester including me owning it for the last twelve Months without any cover over it and I took mine to Loe Bank Motors where Chris Sanderson removed it, dried it out and re-installed it for just over £100 and it was fine, although I started getting problems with it again as I still haven't cleared my drain holes (I'm my own worst enemy sometimes). Good luck with it mate.
Andy Bruce.